Avoided antiferromagnetic order and QCP in CeCoIn5
We measured the specific heat and resistivity of heavy fermion CeCoIn5 between the superconducting critical field Hc2=4.95 and 9 T, with the field in the [0 0 1] direction, and at temperatures down to 50 mK. These results show that this compound has a quantum critical point (QCP) with the magnetic field as the tuning parameter. For a field of 5 T just above Hc2 the temperature dependence of both specific heat Cp(T) and resistivity ρ(T) show non-Fermi liquid (NFL) behavior down to the lowest temperatures with Cp(T)∝-log(T) and ρ(T)-ρ(T=0)∝T. For fields above 8 T the data exhibit a crossover from a NFL to a Fermi liquid behavior. Specific heat and resistivity data show behavior predicted by spin-fluctuation theory, suggesting that the NFL behavior is due to incipient antiferromagnetism (AFM) in CeCoIn5 with the quantum critical point in the vicinity of Hc2. For fields below Hc2 the AFM phase separated by a QCP from the paramagnetic ground state is not observed, as the system becomes first superconducting. © 2005 Elsevier B.V. All rights reserved.
Publication Source (Journal or Book title)
Physica B: Condensed Matter
Bianchi, A., Movshovich, R., Vekhter, I., Pagliuso, P., & Sarrao, J. (2005). Avoided antiferromagnetic order and QCP in CeCoIn5. Physica B: Condensed Matter, 359-361 (SPEC. ISS.), 74-76. https://doi.org/10.1016/j.physb.2004.12.061